Simulation study on rotor speed of combined rotary separator in coal pneumatic conveying

The separator is a key component of coal pneumatic conveying systems, which plays an important role in improving particle collection efficiency and reducing dust pollution. In this paper, a combined rotary separator was designed. Based on the traditional cyclone separator, the rotor blades were installed and matched with the guide vanes to increase the material separation and collection performance. The influence of rotor speed on the characteristics of the separator was studied by computational fluid dynamics simulation, and the flow field velocity and pressure distribution and the particle trajectory and separation degree were obtained. The results showed that the flow field tangential velocity plays a dominant role in the separation process and is approximately symmetrically distributed with the rotor axis as the center. The velocity of the flow field in the inner rotor is approximately positively correlated with the rotor speed, and the tangential velocity gradually decreases with the increase in the flow field height. The static pressure of the flow field is approximately axisymmetric along the rotor axis, and there is a pressure gradient from the outer separation cone to the rotor axis. The particles in the separator show a separation phenomenon based on the different sizes, and the change trend of the separation degree under different rotor speeds is similar. When the rotor speed is 160 rpm, the particles maintain the highest integrity. The rotor speed of 320 rpm has a protective effect on coarse particles above 1000 µm.